#include <iostream>

using namespace std;

int main(void)
{
    int a = 10;

    int &ref = a;
    // 自动转换为 int * const ref = &a;
    ref = 20; // 内部发现ref是引用，自动转换为 *ref = 20;

    cout << "a = " << a << endl;
    cout << "ref = " << ref << endl;

    return 0;
}